Elevator door control



May 24, 1960 M. A. SCHWEIG ELEVATOR DOOR CONTROL 3 Sheets-Sheet 1 Filed Jan. 28. 1958 Avie/V742 /Vu nae/v 4. 55 0x67 May 24, 1960 M. A. SCHWEIG ELEVATOR DOOR CONTROL 5 Sheets-Sheet Filed Jan. 28, 1958 I ifizzocsys,

May 24, 1960 M. A. SCHWEIG ELEVATOR DOOR CONTROL 5 Sheets-Sheet 3 Filed Jan. 28. 1958.

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.J v .mTfw L a a X a 1 United States Patent ELEVATOR: DOOR CONTROL Malvern A. Schweig, University City, Mo., assignor to Security Fire Door Company, St. Louis, Mo., :1 corporation of Missouri Filed Jan, 28, 1958, Ser. No. 711,726

12 claims. or 268-59) The present invention relates generally to control devices. and. more. particularly to. control devices: for elevator doors and the like.

Various mcansfor controlling the opening and closing of elevator doors; and particularly biparting elevator doors, have been, devised in. the. past. The known means, howaver have been; relatively expensiveto construct and maintain, they have not been; capable of satisfactory operation over; a; wide range of operating; conditions and torque requirements, they have, not provided means to compensate. for shifts, of; therangeof movement of the doors so as to fully open and fully close the doorstevery operating cycle, they have been noisy, and they have been relatively slow operating, Another difficulty that has not been solved heretofore byany known door control is that of providing a control that will rapidly deceleratethe door movement during opening and closing and:yctwill insure that the door will always st p-in the fully open and, closed.- position without bouncing and jarring the door t he-, door operating mechanism, the door controls, and theJatching mechanism if such isgprovided. These andother disadvantages of known elevator door control means are overcome by the present device.

The present control device is. provided: in, one of its important'em-bodiments to control-the movement of;counterbalanced bi -parting elevator doors and the like-which are slidablymounted in a shaft opening. It is anticipated, however; that, the present device could also be used to control other types ofv devices, such as other: types of doors, conveyors and similar devices. The embodiment of the invention. shown and described herein comprises electric motor means operatively connected to counterbalanced-bi parting; elevator; door portions. for moving the door portions; simultaneously in opposite directions to open and -close, a shaft'opening, andcontrol. means connected, tor the motor means for controlling the operation thereof, said; control; means including an AC. voltage source adaptedto be. connected to the motor means for exciting the motor means. to, initiate movement of the door portions, means interposed. between the.A,.C. source and the. motor means-for selectively reversibly connecting the motor to the A..C. source, to change-the direction of rotation thereofand-thereby change the direction; ofmovemeat. ff the-1 dQ E'PQItiQBS, a. D.C.. voltage. source, first switching means for disconnecting the AC. source from the; motor and in the sameoperation connecting the D.C. source thereto to decelerate the motorand retard the movement of the door'portions, and second switching means for subsequently disconnecting the D.C. source fronrthe motor means and in the same operation reconnecting theA.C. source thereto to insure complete opening and closingoff the door.

A principal object of thepresent invention is, to provide a control device for opening and closing elevator doors.

Another obj fitof the invention is, to provide control meansthat-insureco lete opening and closing of" an 2,937,867 Patented May 24, 196 0 elevator door regardless of external conditions which may effect the door operation.

Another object is to reduce to a minimum the noise and vibration associated with opening and closing bi.- parting doors andto reduce maintenance costs associated therewith.

Another object of the invention is to reduce. lost time opening and closingv elevator doors, particularly-elevator doors of the bi-parting type and to speed up the move.- ment of personnel and. equipment in multiple floor build.- mgs.

Another object is to provide control means for elevator doors, and the like. which are, adaptable: to automatic and manual operations.-

Another object is to provide reliable, maintenance free, electrically operated elevator door control, means which control the operating speed of elevator doors within limits even though the delivered torque may vary widely due to friction, wear, and other natural conditions.

Another object of the invention is to provide means for smoothly and quickly decelerating elevator doors.

Still another object is to provide an elevator door-control which is adaptable for installation. as original equipment and as an improvement to existing equipment.

These and other objects and advantages of the present invention will become apparent after considering the following detailed description of a preferred embodiment in conjunction with the acompanying drawings.

In the drawings:

Fig. 1 is a front elevational view showing an elevator shaft opening closed by a bi-parting elevator door,

Fig. 2 is a horizontal sectional view taken on line 22 of Fig. 1,

Fig. 3 is a front elevational view similar to, Fig. 1 but showing the bi-parting door in the open position.

Fig. 4 isa: cross-sectional elevational view taken vertically along the line 4--4 in Fig. 3 and extended to show the adjacent openings in the elevator, shaft, and

Fig. 5 is a schematic wiring diagram of a device for controlling the operation of the bi-parting elevator door of Figs. 14.

Referring to the drawings by-reference numbers, number 10 (Figs. 1, 3 and 4) refers generally-to a bi-parting elevator door positioned to open and close a shaft opening 11. The bi-parting door 10 has anupper panel 12 and a lower panel 14 which are slidably positioned in spaced vertical track members or channels 16 and: 18. The upper panel 12is counterbalanced with the lower panel 14 bychains 20 and 22 which are connected between the panels as shown and extend therefrom upwardly over sheaves 24 and 26 located adjacent to the upper corners of. the shaft opening 11. It is now apparent that when the upper panel 12 moves upwardly the chain connections to the lower panel 14 will cause the lower'panel 14 to move downwardly and vice versa. It is also apparent that when the upper panel 12 is in the lower position the lower panel 14 is in the upper position. and the door 10 is closed (Fig. 1); and vice versa when theupper panel 12 is in the upper position the lower panel 14 is down and the door is open (Fig. 3).

A motor 28 is mounted in the wall or on a cross member 29 above the door opening 11 and when energized, as will be described hereinafter, opens and closes the door 10. The motor 28 is connected to a gearbox 30 which carries a gear 32, and thegear 32 ismeshed on opposite sides thereof with gears 34 and 36. The gears 34 and 36 are mounted on shafts 38 and 40 respectively with sprocket gears 42 and 44 respectively; The sprockets 42 and 44 are connected with similar sprockets 46 and 48, respectively on shafts 50 and 52 by link; chains 54 and 56. The shafts 50 and 52 also carry the sheaves;24, and 26. respectively over which the. d r counterbalancing r g L chains 20 and 22 are suspended. When the motor 28 rotates in one direction, the sheaves 24 and 26 are rotated to ,open the door 10, and when the motor 28 rotates in the opposite direction the sheaves 24 and 26 rotate to close the door 10.

The control means for the motor 28 are important to the present invention and a preferred embodiment will be described in detail in connection with Fig. 5 of the drawings. In the description reference will be made from time to time to mechanically operated limit switches which are mounted in the shaft and actuated by the movement of the elevator car 58 and the door 10 during specified preselected spans of the car and door movement respectively. The mechanically operated limit switches are shown in Figs. 1 and 3.

Limit switch 60 is mounted on the wall of the shaft adjacent to an upper corner of the shaft opening, and has an actuating roller 62 mounted on a sidewise extending arm 64. The switch 60 indicates the closed condition of the door 10 and a similar switch is provided for each shaft opening 11. In Fig. 5 the switch 60 is identified by the letters CL and also by the numbers 60' and 60 for two floor locations. When the door 10 is closed a vertically extending cam actuator 66 which is mounted on the lower door portion 14 engages the roller 62 and actuates the switch 60. When switch 60 is actuated its contacts are in the open condition (Fig. 5). The ends of the actuator 66 are beveled at 68 and 70 to provide smooth engagement with the associated limit switch rollers.

Another limit switch 72 is mounted on the wall of the shaft adjacent to the bottom of the shaft opening 11 and is actuated by the cam actuator 66 when the door 10 is open with the lower door portion 14 down (Fig. 3). The switch 72 has an actuating roller 74 connected thereto by an arm 76. In Fig. 5 the switch 72 is identified by letters L and numbers 72 and 72".

Another limit switch 73 is also mounted to the wall of the shaft and has a roller 80 connected thereto by an operating arm 82. A cam actuator 84 with beveled end portions 86 and 88 is mounted on the elevator car and engages the roller 80 to actuate the switch 78 when the elevator car 58 is in the leveling zone adjacent to the shaft opening 11. The switch 78 is referred to as the zone switch and indicates when the car is in the leveling zone for the particular shaft opening. A similar zone switch is associated with each shaft opening. Each zone switch 78 has a plurality of switching contacts associated therewith. In Fig. two sets of zone contacts are shown to illustrate the connections for two floors in a building. The zone switch contacts are identified in Fig. 5 by the letter Z and are further identified at one floor as 78 and 78 and the corresponding switches at the other floor are indicated as 78" and 78,,.

In order to more fully understand the electrical controls it will be advantageous to first briefly describe what is to be accomplished thereby. Briefly, the present control is constructed to initially apply an A.C. voltage to the windings of the motor 28, which motor is shown having three phases and is preferably a squirrel cage induction motor having a relatively high resistance winding to be able to withstand full load conditions for a considerable time interval without damage. The motor is also selected to have the desired speed torque characteristics.

With the initial A.C. applied, the motor accelerates the door from an at rest condition (in the open or closed direction depending on the condition of the door) at a fairly high rate of speed but not so fast as to endanger the safety of those in the area or strain the door mechanism. When the door has traveled a substantial portion of the total distance required, the A.C. is removed from the motor and a D.C. voltage is applied to decelerate the motor and the door. The range of door movement over which the DC is applied, and the strength of the DC. source, are selected to stop the door at approximately the fully open or fully closed position depending on the direction in which it is moving.

If, however, the door has not moved all of the way to the fully closed or fully opened position, the motor 28 is again energized, this time by a reduced A.C. source, and completes the operation at reduced torque and speed.

Initiation of the opening and closing cycles is through open and close spring restored switches and 102 respectively which are usually mounted in the wall of the elevator car 58. As will be noted hereinafter, actuation of the open switch 100 results in a full cycle of operation in which the door is fully opened, while actuation of the close switch 102 maintains a closing cycle only while the switch 102 is depressed and release of the switch (during the greater part of the cycle) will cause the operation to stop. The principal reason for not making the closing operation self sustaining is to overcome a potential safety hazard, and it is anticipated that both operations could be made self sustaining if desired.

Referring now to Fig. 5, number 104 refers to a three phase A.C. power source or transformer which supplies power to the door control by leads 106, 108 and 110. The upper portion of the circuit identified generally by number 112 is the power portion of the circuit and the lower portion identified by number 114 is the control portion.- An isolation transformer 116 is connected between the upper and lower portions 112 and 114 although this is not necessary to the operation and may be omitted if desired.

The power portion 112 of the circuit is controlled by the control portion 114 and includes the motors 28, 28" and so on (one being provided for each door in the shaft). The door controls can be installed at a remote location such as in a control room over the elevator shaft or they can be carried by the elevator car 58. The limit switches which are controlled by movement of the car and the door, however, are usually mounted on the shaft wall and one set is required to operate each door in the shaft.

The motors 28, 28" and so on depending on the num ber of floors, are connected in parallel through the zone switches 78 and 78", and since only one zone switch can be actuated at any one floor, only the motor at that particular floor can be energized when the car 58 is there. In this description the controls will be considered only at one floor (indicated by the single primes following the number) and it will be understood that a similar control is available at every other floor.

One phase winding 118' of the motor 28' is connected to the A.C. source by the lead 106. The other two motor phase windings 120 and 122 are alternatively connected to the other A.C. source leads 108 and depending on the direction of motor rotation. For example, lead 108 is connected to the motor winding through normally open relay contacts FO-4, through one of three parallel branches consisting respectively of normally open relay contacts OD-S and FO-6, normally open relay contacts CD-6 and FC-6, and resistor 124; through normally open relay contacts 00-3, and through zone contacts 78 which are closed when the elevator is at that floor.

Lead 110 is connected by a similar circuit to the same motor phase winding 120' through normally open relay contacts FC-4 instead of through the contacts FO-4.

The motor phase winding 122' is connected to lead 110 through normally open relay contacts FO5 and CO4 and through the zone contacts 78' associated therewith. The winding 122' is also connected by a similar circuit to the lead 108 through normally open relay contacts FC-S instead of through the contacts FO-S.

The motor winding 122' is also alternatively connected to the lead 110 through a circuit consisting of normally open relay contacts BR-2, rectifier 126, and normally closed relay contacts OC-I. A circuit consisting of qana i r ndnormally, ose lay conta ts. QQ-fi is connected'between the motor side of the rectifier 12,6 andthe; lead 106.

Brimary winding;13 ,0. of the isolation transformer 116 is also cdnnccted, between, the leads 106, and 110, and thesecondary 132, is connectedacross leads 134; and, 136 whichsupply. power to the control portion 114 of the circuit-. Thelead 134.is ,pr.ovided witha fuse 138, and the lead..136, is rounded.

Areset, circuit is, connected across the leads134 and l3,6 and consistsof a: reset relay RS (of a known type) in,.serie s-r with, a parallel circuit, onebranch consisting of a normally open spring restored reset switch, 140 and the: other branch of normally open reset relay contacts RSF-Z, in series with normally closed timing relay contacts Mel When the: reset, switch 140 is depressed, the reset relayRS energizes andcloses its RS-Zcontacts establishiug; a, self-holding circuit therefor. At the same time reset relay contacts RS-1. close and establish a power connection: from lead 134 to the rest of the control circuit 114.

Thevarious relays shown in Fig. are identified by descriptive, letters thereon and the contacts which. are operated by.-the-relaysare identified by the same descriptiveletteringfollowed by. the appropriate number. In order to further simplify the description the relay contacts are allv showninthe position that they are in when the. associated. relay is deenergized. For example, two parallel, spaced lines indicate a set of normally open contacts and spaced parallel lines, with a line angularly extended therebetween indicates a set of normally closed contacts,

timer relay (or motor) M is shown connected across the leads 134 and 136 below the, reset relay RS and is inseries with,threeparallel normally open branches, one consisting of, relay contacts FO-S, one of relay contacts ETC-7,, and the third relay contacts, BR,3. The timer relay, when energized, takes a certain predetermined amount of time; before its contacts transfer. This time is, adjusted to exceed the operating period of the door sothat, if thedoor is binding excessively or blocked the reset relay RS will drop out and the motor contacts will opento deenergize themotor28' before it isv damaged.

Below. the timer relay M, circuit are a; plurality of parallehcontrol, circuits, all under control of a normally closed springrestored, stopswitch 142 which when actuatedrdeenergius the controlcircuits. The control circuits also .dep endtfor enertgizationon one. of the zone switches, suchaathe switchesjfi, and 7,89 being closed indicating that; theieleyator car. 5 8,.isszin; a landing zone.-

The upper control circnitrdependent onthe stop switch 141.consistsofa plurality of the-normally closed limit .W t h s..7 ,,7,2':' (on eing p videdfor each d r.

connected in series with an open sequence relay 0D. The switches; 72,, 72., and; so; on, areclosed when the door It),is;c 1ose.d andopenwhenthedoor 1,0-is, open (Figs. 1 and,3 Thereforerwheneverthe elevator car 58;is in a leyclingzone. withthedoor. 10 closed, thetrelay OD is energized:

.102 closed; the relay F0 will beenergized and will be held-energized when the switch100 is released by-contacts Another-circuit is connected in parallel with the hold circuit for relay FQ and consists of a normally open timingmotor contact TM-2 and relay contacts F0-3. This circuit is provided to hold therelay F0 energized fora predetermincd time which may be adjusted'to extend #ftcrthe.v relay 0D has been deenergized. by the 6 Qpcninsm mcnt the r opening, the limit switch 72'.

Acircuit is also provided across the series-combination of] the relay F0 and the contacts FC-2. This circuit consists of relay contacts FO-Z which is connectedto the series circuit of door sequence relay 0C and. parallel branches, one consisting of timer relay contacts TM-1' and the other ofrelay contacts CD-7 and OD-6' in series.

Below and connected to the circuits lastdescribed' is a door closing circuit consistingof the series combination of the spring restored close switch 102', relay contacts FO-l and door closing relay FC. Thejclosing circuit is connected to the opening circuit by" a circuit consisting of series connected relay contactsCD-Z and OD-7 which circuit is connected between the common. sidesof contacts TM'2 and FO-Sand' the common sides, of the close switch 102andcoutacts-FO-1. The cl'osingcircuit also consists of relay contacts F03. connected between the common sides of contacts FLT-.2 and" relay QC and the common sides of FQ-l and relay FC,

Since the contacts FO-l in thecircuit of the close relay PC are normally closed, actuation of the close switch 102 directly energizes the close relay PC, It should be noted, however, thatnohqldcircuit isp foyided for the close relay PC as there is for the open relay F0 until the door is nearly closed. Whenthfe door ispartly closed the open limit switch associated therewith closes to energize the opensequence relay OD anda hold-circuit is then established for the close relay PC to complete the closing operation. This holdj circuitis through the normally open timer contacts TM -2 which are closed, through the normally closed contacts CD72. which, are closed because of the limit switch ,60 and through the normally open contacts OD-7whichare closed whenrelay OD is energized by the limitswitch72.

Below the above circuits is a, closed sequencecircuit consisting of a, closed sequence relay, CD, connected, in series with the parallel connected. close limit, switches 60', 60 and so on. The. limit switches 6 0.', 60 andjsoonare all normally open and each closes when the door, 10 associated therewith is opened a predetermined amount.

A timing motor circuit is shownconnected below the closed sequence circuit and consists. of a timing motor TM connected in series, with two, parallel" branches, one consisting of timing motor contacts,TM.-3. in. seriesfwith parallel connected relay contactsv CD-3 and OD.1;. and the other consisting of timing motor contacts 'I M4, in series with relay contacts 012-5 and OD..4.. Since the timing motor contacts,TM-4 are closedprior. to the initia: tion of an openorclose cycle, thetimiugmotor. TM; will be energized throughthe TM-4. contacts. when the.closed sequence relayCD and theopen, sequencerelay OD are simultaneously energized. Relays OD andCD aresimultaneously energized after, the door hasmoved, partially open or partially closed. Therefore, the;timing motor TM is active during opening andclosingoperations.

The timer motor, TM rotatesa shaft (not. shown) that carries a plurality of timed, cams thereon. One suchlcam is provided to operate each of the, timing motor contacts TM-1,TM-2, TM-3 and, TM-4. After. the timing motor has been energized, the TM-4 contacts, (whichare initially closed) open, andthe TM-3, contacts (which are initially open) close. The timing of these contacts is adjusted to provide a hold circuit for the, timer motor TM which extends even after one of the limit switches. 60; or 72' has again been actuated by movement ofthe door.

It should also be noted that timing motor contactsTM-l are initially closed to provide an energizing circuit, for the door sequence relay 0C. This energizing circuit is broken when the timing motor is energized and; is bypassed by a parallel hold circuit of relay-contacts-CD-7 and OD-G as. previously described which, holds until; the door operation, is substantially. complctedand ig h 60' 01172 is actuated.

A braking relay BR is connected across the secondary 132 of the transformer 116 in series with relay contacts -5 and TB-l. As was previously noted in connec' tion with the power portion of the circuit, the braking relay BR has contacts BR-2 connected in series with the rectifier 126, and this circuit is provided for decelerating the motor. When the braking relay BR is energized by the closing of the 00-5 contacts, the BR-1 contacts also close to establish a self-holding circuit therefor.

The BR-l contacts also close a circuit consisting of a brake limiting relay TB and relay contacts OC-2. This energizes the relay TB, which is a delayed operation timing relay or timing motor. When the relay TB finally does act it ends the time interval during which braking D.C. voltage is applied because the contacts TB-l open and deenergize the braking relay BR. It should also be noted that when the QC-5 contacts close to energize the braking relay BR, the 00-2 contacts open and prevent energizing the TB relay. Therefore, the relay TB cannot be energized until after door sequence relay 0C is deenergized.

The time interval from when the door sequence relay 0C is deenergized by the opening of the contacts OD-6 (on an opening operation) to the time when the relay 0C is reenergized through TM1 is set at less than the time necessary for the relay TB to open the TB-d contacts. Even if this were not so and the contacts TB-1 opened the original braking cycle after the door opened the limit switch 72', the relay BR would be reenergized through the contacts OC-S when the relay OC reenergized.

During most of an opening cycle, the contacts TM-2 are closed and the open direction relay F0 is held energized through a circuit consisting of the contacts TM-2 and FO-3. The same circuit provides a hold and a reenergizing circuit for the door sequence relay OC through the contacts FO-2, CD-7 and OD-6 and also through the timing motor contacts TM-'1 respectively.

On a door closing cycle the close sequence relay PC is not provided with a self-holding circuit until the door has closed enough for the cam operator 66 to actuate the close limit switch 60. When this happens the close sequence relay CD is deenergized and closes the con tacts CD-Z. Only then is a circuit established to hold the close sequence relay FC and complete the closing operation. This circuit is through the timing motor contacts TM-2, and relay contacts CD-2, OD-7, and FO-l. Up until the time that the close limit switch 60' opens, which covers most of the door movement, there is no hold circuit for the close sequence relay PC as there is during an open operation for the open sequence relay F0 and the operator must keep the close switch 102 depressed. This'feature is provided for safety reasons and obviously is not essential to the operation.

Another function that is important to the operation of the present control involves reenergizing the motor 28' at low speed and torque after a braking operation to assure complete opening or closing of the door in the event that the door is not fully opened or closed after being decelerated. The reenergization of the motor 28' takes place with reduced A.C. voltage and is accomplished by connecting the resistor 124 in series with one of the motor phase windings. To understand this operation the motor circuit operation will be briefly reviewed. When the open switch 100 is actuated, the open direction relay F0 is energized and at the same time the open sequence relay OD is actuated. The energizing of both relays F0 and OD closes the contacts OD-S and FO-6 and connects a short across the resistor 124.

Similarly when the close switch 102 is actuated and the door is open, the close direction relay FC is energized, and the close sequence relay CD is also energized through the appropriate closed limit switch Therefore, when initiating a closing cycle the contacts CD-6 and FC-6 short the resistor 124 and apply full A.C. power to the motor 28'.

- When the door 10 is closed the timing motor contacts TM-3 are open, TM-4 are closed, and contacts CD-S are open, and contacts OD-4 are closed. After the circuit to open the door is initiated and the door opens sufficiently to close the limit switch 60', the close sequence relay CD energizes and the relay contacts CD-S close to start the timing motor TM. After a relatively short time interval. contacts TM-3 close and TM-4 open stopping the timing motor TM. At this point relay contacts CD-3 and OD-l are open and contacts TM-2 and TM-3 are closed.

Recalling now that the braking relay BR is energized by the OC-S contacts and is held by its own contacts BR-1, it is also noted that D.C. power is prevented from being fed to the motor 28' by the relay contacts OC-l. Also D.C. power is prevented from reaching the capacitor 128 by contacts OC-6. As the door opens, relay contacts CD-7 and OD-6 are closed and provide a hold circuit for the door sequence relay OC and the timing motor contacts TM-l open. As the door approaches the fully open position the limit switch 72' opens and deenergizes the open sequence relay OD causing the contacts OD-6 to open and deenergize relay 00. As soon as the relay 0C is deenergized, the contacts OC3 and OC-4 open and remove A.C. power from the motor 28', the contacts OD-S remove the short around resistor 124, contacts 0C1 and 00-6 connect the D.C. power braking circuit to the motor 28' and capacitor 128, contacts OD-l close and start the timing motor TM, and contacts OC-2 close and energize the brake limit relay TB.

After a preselected interval, the timing contacts TM-l again close and reenergize the relay 0C. This disconnects the D.C. power from the motor 28' and reconnects A.C. power thereto. However, with relay OD deenergized the A.C. power to the motor 28 must pass through the resistor 124 thereby reducing the power to the motor so that it operates at reduced torque (and reduced speed) and makes sure that the door moves or has moved to the fully open position and is held there momentarily.

The timing motor TM continues to function during the door operation until the contacts TM-3 open and deenergize the timing motor TM. Simultaneously, the holding circuit for the relay F0 (through FO-3 and TM-2) is open, deenergizing relays F0 and OC. When relay 0C is again deenergized the D.C. braking current is again fed tothe motor 28' and will continue to be fed until the braking limit relay TB completes its delay cycle and opens the contacts TB-l. When this occurs the brake relay ER is deenergized. The deenergizing of brake relay BR opens the contacts BR-l and deenergizes the relay TB.

If during the opening cycle the operator decides to press the stop switch 142, a circuit will be immediately established to decelerate the motor and door. When the stop switch is depressed, the relay 0C is deenergized and closes the contacts 00-1 and 00-6 to apply D.C. to the motor 28' and simultaneously opening contacts 00-3 and 00-4 to remove the A.C. therefrom. However, before the relay 0C is deenergized the contacts 00-5 will have energized the braking relay BR which is self-holding and established a circuit through the contacts BR-2 for the D.C. braking current.

With the exceptions already noted the door closing cycle is similar to the opening cycle, the principal difference being that the close switch 102 must be held in at least until the door has closed enough to open the closed limit switch 60. This is the case because the relay PC is not self-holding but depends on the closed switch 102 being depressed.

It should also be noted that during the closing cycle power to the motor 28' is fed through contacts FC-5 and FC-4 instead of through contacts FO-4 and FO-S 9. and in this way the direction, of motor rotation. is re.- versed by interchanging the, phases.

The motor protection relay M is energized by the closing of any one of the contacts FO-8, FC-7 or BR-3, and is. a delayed action timing device which operates to transfer its contacts only after it has been energized for a preselected interval of time. If the. door fails to complete its cycle or takes longer than the time necessary to transfer the contacts of the relay M, the contacts M-l will open and deenergize the reset relay RS. When this happens the, reset relay contacts RS-l open and remove power from the control portion 114: of the circuit.

A further function of the. instant control is to enable an operator to apply power to, the. motor 28 after the door has been fully opened, or closed, by pressing the appropriate switch 100' or 102. This. function is designed to keep the equipment in operation in. spite of the most adverse conditions such, as might be. caused by faulty adjustment.

It should also he noted' that the physical location of the limit switches. 60', 72' and 78 can be varied by moving them on their mountings. By so, doing. a. Wide latitude of adjustment is provided to. produce a desired operating condition and these adjustments are. simple enough that they can be made by relatively unskilled personnel using simple hand tools.

Thus, a control device has been shown. and described which fulfills all of the objections and advantages sought therefor. Obviously, however, manyvariations, alterations, modifications, and changes can be made in the particular embodiment of the invention. which has been chosen for purposes of description. All such variations, alterations, modifications, and changes which will be readily apparent to one skilled in the art are contemplated as being covered by the present disclosure which is limited only by the claims which follow;

What is claimed is:

1. A control device for elevator doors that are movably mounted in a shaft opening comprising an elevator door movably mounted in a shaft opening, motor means operatively connected to said elevator door, means, connected to the motor means for controlling the operation thereof, said means including a door opening switch and a door closing switch, a first source. of? power adapted to be connected to the motor means by said opening and closing switches for initially effecting opening and closing movement of the elevator door respectively, a second source of power, electric control means including timer means set in motion by the opening and closing switches for disconnecting said first source of power from the motor means when the door has moved a preselected distance and simultaneously connecting said second source of power thereto to decelerate said motor means, and means for disconnecting the second source of power from the motor means and thereafter reconnect a portion of the first source of power thereto for moving the door to the fully open or fully closed position.

2. A control device for a door slidably mounted to open and close an opening in a shaft comprising a source of A.C. voltage, a source of DC. voltage, a door slidably mounted in a shaft opening, motor means operatively connected to said sliding door for moving said door, a door open switch and a door close switch, and electric door control means including first and second time delay switch means operatively connected to the motor means and initiated by actuation of said door open switch and said door close switch, said control means upon being initially actuated connecting the A.C. source to the motor means for energizing the motor means in a direction to move the door and thereafter under control of said first time delay switch means simultaneously disconnecting the A.C. source from the motor means and connecting the DC. source thereto to decelerate the motor, and still later under control of said second time delay switch means simultaneously disconnecting the DC.

10 source from themotor means and reconnecting the: A.C. source thereto.

3. A control device for a door slidably mounted to open and close an opening in a shaft comprising a source of A.C. voltage, a source of D0. voltage, a, door slid.- ablymounted in a shaft opening, motor means operatively connected to said sliding door formoving said door, a door open switch and a door close switch, and electric door control means including first and second time delay switch means operatively connected to the motor means and initiated by actuation of said door open switch and said door close switch, said second time delay switch means including means for tapping off a portion only of the A.C.. source, saidcontrol means upon being initially actuated connecting; the A.C. source to the motor means for energizing the motor means in a direction to move the door and thereafter under control of said first time delay switch means simultaneously disconnecting the A.C. source from the motor means and connecting the DC. source thereto. to decelerate the motor, and still later under control of said second time delay switch means simultaneously disconnecting the DC. source from the motor means and reconnecting a portion only of the A.C. source thereto.

4. A control device for a bi-parting elevator door slidably mounted in a shaft opening comprising an A.C. source of power, a DLC- source of power, a bi-parting elevator shaft door, motor means operatively connected to said door for moving said door between an open and closed condition in. a shaft opening, and electric. control means for energizing the motor means including, a door open switch for energizing the motor means in a direction to slide the door toward an open position, a door close switch for energizing the motor means in a direction to slide the door toward a closed position, said open and close switches upon initially being actuated connecting the motor means to the A.C. source of power, and. limit switch means actuated by the door when moved to an advanced position during opening and closing thereof for simultaneously disconnecting the A.C. source from the motor and connecting the DC. source thereto to decelerate the motor, said limit switchmeans including timed means for still later disconnecting the DC. source. from the motor and reconnecting the A.C. source. thereto.

5'. A control device for a. bi-parting elevator door movably mounted in a shaft opening comprising an A.C. source of power, a DC. source of power, a bi-parting elevator shaft door movably mounted in a shaft opening, motor means operatively connected to said door for moving said door between an open and closed position in the shaft opening, and electric control means for energizing the motor means including a door open switch for energizing the motor means in a direction to move the door toward an open position, a door close switch for energizing the motor means in a direction to move the door toward a closed position, said open and close switches upon being initially actuated connecting the motor means to the A.C. source of power, and timed delay switching means energized by actuation of the open and close switches for disconnecting the A.C. source from the motor means at a preselected position of door movement and simultaneously conencting the DC. source thereto to decelerate the motor means and the door movement, said time delay switching means including means for timing the application of said D.C. source to stop the door at substantially the fully open and closed positions depending upon whether the open or closed switch was actuated and for disconnecting the DC. and simultaneously reconnecting the A.C. source to the motor neans to assure complete opening and closing of the cor.

6. A control for counterbalanced sliding doors mounted in a track and movable for opening and closing a shaft opening comprising an induction motor operatively connected to said door for moving the door in the track,

11 a limit switch mounted adjacent to said door and operated by the door at a preselected position of door movement, and electric control. means including an A.C. power source, a DC power source, and an open and close switch for selectively effecting movement of the door in a desired direction, said control means upon being actuated by said open or close switch connecting the A.C. power source to the motor to effect movement of the door in the track, and thereafter said control means being effected by said limit switch to disconnect the A.C. power from the motor and to connect the DC. power thereto for decelerating the motor to stop the door, and time delay control means included in said electric control means and set in motion during the movement of the door for disconnecting the DC. power from the motor and thereafter reconnecting the A.C. power thereto to assure that the door reaches the fully open and closed position for every operating cycle thereof.

7. The control for a counterbalanced sliding door defined in claim 6 wherein a stop switch is provided to advance the decelerating operation of the door and motor upon actuation thereof.

8. The control device for counterbalanced sliding doors defined in claim 6 wherein said electric control means includes a timer device for disconnecting the A.C. and DC. sources from the motor whenever a door operation exceeds the timing of said device.

9. A control device for a bi-parting elevator door slidably mounted in a shaft opening comprising an A.C. source of power, a DC. source of power, a bi-parting elevator shaft door mounted in a shaft opening, motor means operatively connected to said door for moving said door between an open and closed condition in the shaft opening, and electric control means for energizing the motor means including a door open switch for energizing the motor means in a direction to slide the door toward an open position, said door open switch including self-holding means for maintaining the electric control means energized to complete a door opening operation, a door close switch for energizing the motor means in a direction to slide the door toward a closed position, said open and close switches upon initially being actuated connecting the motor means to the A.C. source of power, and limit switch means actuated by the door when moved to an advanced position during opening and closing thereof for simultaneously disconnecting the A.C. source from the motor and connecting the DC. source thereto to decelerate the motor, said limit switch means including timed means for still later disconnecting the DC. source from the motor and reconnecting the A.C. source thereto.

10. Control means for elevator doors opening and closing the landing openings in an elevator shaft, comprising a landing opening door, motor means connected to said door to move the same to open and close the landing opening, door opening control switch means, door closing control switch means, and an electric'circuit system connected to said motor means and said door opening and closing switch means, said circuit system including a first power source for said motor connected through said control switch means, a second source of power for said motor, and power shifting means in said circuit system adapted upon predetermined door movement in opening and in closing the landing opening to shift thev motor over to said second source of power to decelerate the motor means and bring the landing door towards a stop, said power shifting means including means for reconnecting the motor to said first power means whenever the door has stopped before being fully opened or closed.

11. The control means for elevator doors defined in claim 10 wherein a timed overload switch is provided for de-energizing the electric circuit system when the opening and closing of the door exceeds a preselected timing interval. 1

12. The control means for elevator doors defined in claim 10 wherein said electric circuit system includes stop swicth means adaptable upon actuation thereof to advance the shifting of the motor to said second source of power to prematurely decelerate the motor means and stop the door.

References Cited in the file of this patent UNITED STATES PATENTS 2,154,314 Minneci Apr. 11, 1939 2,499,979 Smith Mar. 7, 1950 v FOREIGN PATENTS 531,907 Great Britain Jan. 14, 1941 

